Pool cleaning robot having a filtering unit and a sensor

Abstract

A pool cleaning robot that may include a filtering unit for filtering fluid that passes through the filtering unit; a calorimetric sensor for sensing a cleanliness related parameter of the filtering unit while the pool cleaning robot is submerged in the fluid; and a controller that is configured to at least assist in determining, based on the cleanliness related parameter of the filtering unit, a cleanliness of the filtering unit.

We claim: 
     
       1. A pool cleaning robot, comprising: a filtering unit for filtering fluid that passes through the filtering unit; a calorimetric sensor for sensing a cleanliness related parameter of the filtering unit while the pool cleaning robot is submerged in the fluid; and a controller that is configured to at least assist in determining, based on the cleanliness related parameter of the filtering unit, a cleanliness of the filtering unit; wherein the calorimetric sensor comprises a first thermal resistor and a second thermal resistor that are spaced apart from each other and are thermally isolated from each other until the fluid thermally couples the first thermal resistor to the second thermal resistor. 
     
     
       2. The pool cleaning robot according to  claim 1 , wherein the pool cleaning robot comprises a turbulence generator and wherein the turbulence generator is static. 
     
     
       3. The pool cleaning robot according to  claim 1 , wherein the pool cleaning robot comprises a turbulence generator and wherein the turbulence generator is dynamic. 
     
     
       4. The pool cleaning robot according to  claim 1 , wherein the pool cleaning robot comprises a turbulence generator and flow limiters; and wherein the turbulence generator is positioned between the flow limiters. 
     
     
       5. The pool cleaning robot according to  claim 1  wherein the pool cleaning robot is configured to heat the first thermal resistor, and measure an electrical parameter of the second thermal resistor. 
     
     
       6. The pool cleaning robot according to  claim 1  further comprising an accelerometer that is also configured to sense the cleanliness related parameter of the filtering unit while the pool cleaning robot is submerged in the fluid. 
     
     
       7. The pool cleaning robot according to  claim 6  wherein the accelerometer is configured to sense the cleanliness related parameter based on frequencies of noise vibrations sensed by the accelerometer. 
     
     
       8. The pool cleaning robot according to  claim 6  wherein the accelerometer is configured to sense the cleanliness related parameter based on amplitude and frequencies of noise vibrations sensed by the accelerometer. 
     
     
       9. A method for monitoring a pool cleaning robot, the method comprises: filtering, by a filtering unit of the pool cleaning robot, fluid that passes through the filtering unit; sensing, by a calorimetric sensor, a cleanliness related parameter of the filtering unit while the pool cleaning robot is submerged in the fluid; wherein the calorimetric sensor comprises a first thermal resistor and a second thermal resistor that are spaced apart from each other and are thermally isolated from each other until the fluid contacts both the first and second thermal resistors; assisting in determining, by a controller of the pool cleaning robot and based on the cleanliness related parameter of the filtering unit, a cleanliness of the filtering unit. 
     
     
       10. The method according to  claim 9 , wherein the pool cleaning robot comprises a turbulence generator and wherein the turbulence generator is static. 
     
     
       11. The method according to  claim 9 , wherein the pool cleaning robot comprises a turbulence generator and wherein the turbulence generator is dynamic. 
     
     
       12. The method according to  claim 9 , wherein the pool cleaning robot comprises a turbulence generator and flow limiters; and wherein the turbulence generator is positioned between the flow limiters. 
     
     
       13. The method according to  claim 9 , comprising wherein the sensing comprises heating the first thermal resistor to a predefined temperature and sensing a temperature of the second thermal resistor. 
     
     
       14. The method according to  claim 13  further comprising sensing, by an accelerometer, the cleanliness related parameter. 
     
     
       15. The method according to  claim 14  wherein the sensing by the accelerometer is based on frequencies of noise vibrations sensed by the accelerometer. 
     
     
       16. The method according to  claim 14  wherein the sensing by the accelerometer is based on amplitude and frequencies of noise vibrations sensed by the accelerometer. 
     
     
       17. The method according to  claim 9  comprising determining the cleanliness related parameter in response to an expected pattern of operation of the pool cleaning robot. 
     
     
       18. The method according to  claim 9  comprising determining the cleanliness related parameter in response to flow changes through the filtering unit.